https://help.ubuntu.com/community/Firestarter

Also, I misspoke on the firewall always on.

I found that the firewall is not on by default but that the ports are
closed until they are opened.


Okay. Echolink is a p2p app, so lets break this down.
How do you access the net? Broadband: cable, dsl, wireless.
Any of these will require some type of modem:
cable - mine is a Motorola with built in wireless router and firewall
dsl - can be similar
wireless - the radio is your modem and has neither router or firewall

If you are sure your modem as NO router or firewall enabled, the next
thing is to check your ports.
....

Just saw you posted your situation so Ill read that first....

On firestarter click on the Policy tab. on the Bottom Pane where it says
Allow Service for right click and chose Add Rule

In the name field add Echolink and in the port field add 5200.
Under "When the source is ...", if this is open to anyone and you dont
know who it will be, choose anyone.
Click add and then click Apply.

Do this for the ports you need open.

Afterwards you can run netstat -l -t and then lsof -i at the command
line and see what port is being listened to.